One of our cats is recovering from an ear infection. (Yes, it’s going around. No, cat drops don’t hurt humans. I digress.) He is better but still wobbly, too wobbly to jump to the top of the fridge where the free-choice dry cat food lives. (Fear not – everyone gets an cat-appropriate dollop of canned food at night check. No one starves around here. End of second digression.) Instead, he gets a chance to eat dry food on the floor behind closed doors. He won’t eat it. OTOH, he will eat the dry food if he is lifted up to where the big cats eat.
It’s the same food!!
Virtual Brush Box 
Ah, see, I have two human children. So, you know, DUH!
Like sleeping on the left or right side of the bed. It’s the same bed!
Animals are funny like that. My gerbil will only drink from a plastic bottle, not a glass one. How he even knows the difference I have no idea.
Probably taste, which makes me wonder why we drink out of plastic bottles.
Place matters.